I agree with Saba being a downgrade. Her facial expressions are now much better, but there's no denying that Gura was a homerun design while Saba is a bit too generic.
Dooby is a better design than Ame, and it's not even close. Ame had the most lackluster design in all of EN, at least Dooby has a partially interesting one.
Nimi could have been a better design than Fauna, but ultimately isn't. I actually really like her chibi model and had the full model bought closer semblance to it, that would have been so much better. But as it stands, it's still a good design and in fact the strongest of the three here. It just doesn't beat out the Fauna design, which is top tier.